At least 20 people were shot dead in Texas after a gunman opened fire at a church during Sunday services in Sutherland Springs, Texas.

Local media reported that Wilson County Commissioner Larry Wiley quoted an emergency responder as saying that between 20 and 24 people were killed, and around 20 were wounded when a man walked into the church about 11:30 a.m. on Sunday and opened fire at the crowd of people.

The gunman, according to Wiley, was killed roughly nine km away in Guadalupe County after being cornered by deputies.

At least eight injured are being treated at University Hospital in San Antonio, Spokeswoman Leni Kirkman said, adding the hospital may receive more patients.

The Wilson County News earlier quoted Sheriff Joe Tackitt as reporting that there have been 'multiple casualties and fatalities'.

Texas Governor Abbott released the statement on the shooting. "While the details of this horrific act are still under investigation, Cecilia and I want to send our sincerest thoughts and prayers to all those who have been affected by this evil act. I want to thank law enforcement for their response and ask that all Texans pray for the Sutherland Springs community during this time of mourning and loss."

The shooting incident occurred on Sunday in a church in Sutherland Springs, about 300 km west of Houston, Texas.

The shooting reportedly happened at the First Baptist Church of Sutherland Springs, approximately 35 km southeast of San Antonio.

U.S. President Donald Trump tweeted "May God be w/ the people of Sutherland Springs, Texas. The FBI & law enforcement are on the scene. I am monitoring the situation from Japan."

Sutherland Springs is an unincorporated community located on the old Spanish land grant of Manuel Tarin in northern Wilson County. According to the Handbook of Texas, the population was 362 in 2000.